1,3-Benzodioxol derivatives

ABSTRACT

1,3-Benzodioxol derivatives, the new compounds, represented by the formula: ##STR1## AND THE PHARMACOLOGICALLY ACCEPTABLE ACID-ADDITION SALTS THEREOF ARE PROVIDED, WHEREIN R 1  and R 2  are lower alkyls or the both together may form a divalent alkylene, R 3  is a lower alkyl, phenyl, halogen-substituted phenyl or benzhydryl group, n is an integer of 2 or 3, and X stands for carbonyl (CO) or methylene (CH 2 ) bridge. The compounds in which X stands for the methylene exhibit durable anti-histamic activity with low toxicity, and are useful for therapeutic purposes, while the compounds in which X stands for the carbonyl bridge are easily convertible by reduction into the former compounds.

This is a division of application Ser. No. 609,145, filed Aug. 29, 1975,which application is in turn a division of application Ser. No. 503,515,filed Sept. 5, 1974, U.S. Pat. No. 3,981,864.

This invention relates to 1,3-benzodioxol derivatives, the newcompounds. More particularly, the invention relates to 1,3-benzodioxolderivatives represented by the following formula: ##STR2## wherein R₁and R₂ are lower alkyls or the both together in interconnection may forma divalent alkylene as a member constituting a cyclic structural moiety;R₃ is a lower alkyl, phenyl, halogen-substituted phenyl or benzhydrylgroup, n is an integer of 2 or 3, and X stands for carbonyl (CO) ormethylene (CH₂) bridge, and a process for the synthesis thereof.

It has been found that the new compounds of this invention possessanti-histamic activity and in particular 1,3-benzodioxol derivatives ofthe abovementioned formula (I) wherein X stands for the methylene bridgepossess durable antihistamic activity with low toxicity.

1,3-Benzodioxol derivatives of the formula (I) wherein X stands for thecarbonyl may be prepared, for example, by the following schematicequation: ##STR3## wherein R₁, R₂, R₃ and n have the meanings same asthose defined with respect to the formula (I) aforementioned. Thus, theamide compound of the formula (IV) is obtained by subjecting2,2-di-lower-alkyl-substituted 1,3-benzodioxol-5-carboxylic acid of theformula (II) or a reactive derivative thereof to reaction with1-substituted 1,4-diazacycloalkane of the formula (III).

Preferable class of the reactive derivatives of the starting carboxylicacid compound of the formula (II) is the corresponding acid anhydride,mixed acid anhydride, acid halide, and reactive ester thereof. Thereaction can advantageously be effected in the presence of an organicsolvent inert to the reaction system, such as benzene, toluene, xylene,acetone, pyridine and the like. The contemplated reaction can beperformed smoothly by the addition of an acid-binding agent, such aspyridine, triethylamine, alkali carbonate, cuastic alkali and the like,to the reaction system, when the acid halide, such as acid chloride, ofthe carboxylic acid derivative of the formula (II) is employed. Pyridinewill serve both as the acid-binding agent and also the solvent in thesystem.

On the other hand, 1,3-benzoidioxol derivatives of the aforementionedformula (I) wherein X stands for the methylene may be obtained by thereduction of the compound of the formula (IV) in accordance with thefollowing chemical equation: ##STR4## wherein R₁, R₂, R₃ and n have themeanings same as those defined in the preceding formulae.

In carrying out the reduction procedure, there may be employed, forexample, the method wherein a metal complex compounds such aslithiumaluminium hydride, sodium dihydrobis(2 -methoxy,ethoxy)aluminateand the like, and the method where a high pressure and high temperaturegaseous hydrogen is employed in the presence of cupper-nickel catalyst.

As solvent for recrystallization of the resulting reduction product,there may be employed with good result any of lower alcohols, such asmethanol, ethanol, propanol and a mixture of any of said alcohols withethyl ether.

The resultant compounds (I), if desired, may be converted into thepharmacologically acceptable acid-addition salts thereof in accordancewith a conventional salt-forming procedure. As the pharmacologicallyacceptable acids preferable for the formation of the acid-additionsalts, there may be mentioned inorganic acids such as hydrochloric,sulfuric, nitric and the like acids; and organic acids such as acetic,citric, tartaric, oxalic, fumaric, maleic, methane-sulfonic and the likeacids.

Anti-histamic activity presented by the compounds of the presentinvention was measured on the isolated organs obtained by extirpationfrom guinea-pig or rat by means of Magnus apparatus as follows:

EXPERIMENT 1

With2-methyl-2-ethyl-5-(N-benzhydryl-piperzino-N'-methylene)-1,3-benzodioxol,the product of Example 9 hereinafter-mentioned

Contraction of the isolated ileum under external tension caused by onegram load to be produced by applying 10⁻⁷ g/ml of histamine wasretardatively controlled to an extent of % of the expected normalcontraction, when the ileum has previously been treated with 10⁻⁵ g/mlof said compound. It has further been found that said retardativebehavior did not disappear when the treated ileum was rinsed withTyrode's solution more than 5 times in the interval of 3 minutes. Thefact apparently substantiates that the compound possesses durableanti-histamic activity.

EXPERIMENT 2

With 5'-(N-methyl-homopiperazino-N'-methylene)-spirocyclohexano-1',3'-benzodioxol, the product of Example 15 hereinafter-mentioned, thefollowing several MEC (Minimum Effective Concentrations) have beenobserved.

    ______________________________________                                                             MEC                                                      ______________________________________                                        Anti-histamic activity                                                                              10.sup.-5 g/ml                                          Anti-serotonine activity                                                                            10.sup.-5 g/ml                                          Control: Cyproheptamine                                                                             2 × 10.sup.-6 g/ml                                Anti-cholinergic activity                                                                           10.sup.-5 g/ml                                          Uterine relaxation activity                                                                         10.sup.-5 g/ml                                          Control: Isoxsuprine  10.sup.-5 g/ml                                          Intestinal organ relaxation activity                                                                10.sup.-5 g/ml                                          Control: Papaverine   10.sup.-6 g/ml                                          ______________________________________                                    

Toxicity in I. P. A. (Intraperitoneal administration):

No appreciable toxic symptom appeared with 100 mg/kg.

It is evident from the above ovservations, the new compounds of thepresent invention exhibit and the marked antihistamic, anti-serotonine,anti-choline and the like activities characterized their gooddurability, and accordingly, they are highly useful as anti-histamicagent for therapeutic treatments.

The following Examples serve to illustrate the invention but they are ofcourse, not intended to limit it thereto.

EXAMPLE 1 Synthesis of2-methyl-2-ethyl-5-(N-benzhydrylpiperazino-N'-carbonyl)-1,3-benzodioxol

3 Grams of 2-methyl-2-ethyl-1,3-benzodioxol-5-carboxylic acid aredissolved in 4 ml of pyridine. To the resulting solution underice-cooling with stirring, there are added 1.5 grams of thionylchloride. After continuing the stirring for further 10 minutes, thereare added 3.7 grams of N-benzhydryl-piperazine, and the mixture isheated on water bath for 30 minutes. Ice-water is added to the reactionmixture, and the acidic solution is made alkaline by neutralizing with a5% aqueous sodium hydroxide solution. Oily substance separated out isextracted with ethyl acetate ester. The esteral extract is washed withwater, dried on magnesium sulfate, and the solvent is distilled off fromthe dry extract. There are obtained 4.5 grams of the residue. Theresulting product is in a free base which is identified by converting itinto the corresponding hydrochloride as follows:

To a quantity of the residue, there are added a 10% ethanolichydrochloric acid. The solution thus obtained is concentrated underreduced pressure to dryness. The residue is crystallized from ethanoland has a melting point of 200°-210° C. Elementary analysis of thehydrochloride having the presumable formula C₂₈ H₃₀ N₂ O₃.HCl gives thefollowing data:

    ______________________________________                                                     C       H        N                                               ______________________________________                                        Calculated (%) 69.34     6.58     5.78                                        Found (%)      69.37     6.57     5.72                                        ______________________________________                                    

EXAMPLE 2 Synthesis of2-methyl-2-ethyl-5-(N-methyl-homopiperazino-N'-carbonyl)-1,3-benzodioxol

In accordance with the procedure given in the preceding Example,2-methyl-2-ethyl-1,3-benzodioxol-5-carboxylic acid is subjected toreaction with N-methyl-homopiperazine. The product thus obtained isidentified as its hydrochloride having a melting point of 218°-220° C.Elementary analysis of the hydrochloride having the presumable formulaC₁₇ H₂₄ N₂ O₃.HCl gives the following data:

    ______________________________________                                                     C       H        N                                               ______________________________________                                        Calculated (%) 59.90     7.39     8.21                                        Found (%)      59.70     7.51     8.20                                        ______________________________________                                    

EXAMPLE 3 Synthesis of2-cyclohexyl-spiro-5-(N-methyl-piperazino-N'-carbonyl)-1,3-benzodioxol

2-cyclohexyl-spiro-1,3-benzodioxol-5-carboxylic acid is subjected toreaction with N-methyl-piperazine in accordance with the procedure givenin Example 1. The reaction product thus obtained is identified as itshydrochloride having a melting point of 260°-270° C. Elementary analysisof the hydrochloride of the product having the presumable formula C₁₈H₂₄ N₂ O₃.HCl gives the following data:

    ______________________________________                                                     C       H        N                                               ______________________________________                                        Calculated (%) 61.27     7.14     7.93                                        Found (%)      61.24     7.22     8.03                                        ______________________________________                                    

EXAMPLE 4 Synthesis of2-cyclohexyl-spiro-5-(N-benzhydryl-piperazino-N'-carbonyl)-1,3-benzodioxol

2-Cyclohexyl-spiro-1,3-benzodioxol-5-carboxylic acid is subjected toreaction with N-benzhydryl-piperazine, in accordance with the proceduregiven in Example 1. The purposed reaction product thus obtained isidentified as its hydrochloride having a melting point of 218°-222° C.Elementary analysis of the hydrochloride of the product having thepresumable formula C₃₀ H₃₂ N₂ O₃.HCl gives the following data:

    ______________________________________                                                     C       H        N                                               ______________________________________                                        Calculated (%) 71.34     6.58     5.54                                        Found (%)      71.67     6.62     5.53                                        ______________________________________                                    

EXAMPLE 5 Synthesis of2,2-dimethyl-5-(N-methyl-piperazino-N'-carbonyl)-1,3-benzodioxol

2,2-Dimethyl-1,3-benzodioxol-5-carboxylic acid is subjected to reactionwith N-methyl-piperazine in accordance with the procedure disclosed inExample 1. The purposed reaction product is identified as itshydrochloride having a melting point of 230°-240° C. Elementary analysisof the hydrochloride of the product having presumable formula C₁₅ H₂₀ N₂O₃.HCl.1/2H₂ O gives the following data:

    ______________________________________                                                     C       H        N                                               ______________________________________                                        Calculated (%) 56.78     6.83     8.82                                        Found (%)      57.07     6.85     8.86                                        ______________________________________                                    

EXAMPLE 6 Synthesis of2,2-dimethyl-5-(N-methyl-homopiperazino-N'-carbonyl)-1,3-benzodioxol

2,2-Dimethyl-1,3-benzodioxol-5-carboxylic acid is subjected to reactionwith N-methyl-homopiperazine in accordance with the procedure disclosedin Example 1. The contemplated reaction product thus obtained isidentified in a form of its hydrochloride having a melting point of190°-198° C. Elementary analysis of the hydrochloride having thepresumable formula C₁₆ H₂₂ N₂ O₃.HCl.1/2H₂ O gives the following data:

    ______________________________________                                                     C       H        N                                               ______________________________________                                        Calculated (%) 57.21     7.20     8.34                                        Found (%)      57.32     7.27     7.30                                        ______________________________________                                    

EXAMPLE 7 Synthesis of2-methyl-2-ethyl-5-(N-methyl-piperazino-N'-carbonyl)-1,3-benzodioxol

2-Methyl-2-ethyl-1,3-benzodioxol-5-carboxylic acid is subjected toreaction with N-methyl-piperazine in accordance with the proceduredisclosed in Example 1. The resulting reaction product is identified ina form of its hydrochloride having a melting point of 190°-200° C.Elementary analysis of the hydrochloride having the presumable formulaC₁₆ H₂₂ N₂ O₃.HCl.3/4 H₂ O gives the following data:

    ______________________________________                                                     C       H        N                                               ______________________________________                                        Calculated (%) 56.72     7.28     8.26                                        Found (%)      59.32     7.29     7.30                                        ______________________________________                                    

EXAMPLE 8 Synthesis of2-cyclohexyl-spiro-5-(N-methylhomopiperazino-N'-carbonyl)-1,3-benzodioxol

2-Cyclohexyl-spiro-1,3-benzodioxol-5-carboxylic acid is subjected toreaction with N-methyl-homopiperazine in accordance with the proceduredisclosed in Example 1. The contemplated reaction product thus obtainedis identified in a form of its hydrochloride having a melting point of233°-237° C. Elementary analysis of the hydrochloride having thepresumable formula C₁₉ H₂₆ N₂ O₃.HCl gives the following data:

    ______________________________________                                                     C       H        N                                               ______________________________________                                        Calculated (%) 62.20     7.41     7.63                                        Found (%)      62.04     7.48     7.82                                        ______________________________________                                    

EXAMPLE 9 Synthesis of2-methyl-2-ethyl-5-(N-benzhydryl-piperazino-N'-methylene)-1,3-benzodioxol

4.0 Grams of2-methyl-2-ethyl-5-(N-benzhydryl-piperazino)-N'-carbonyl-1,3-benzodioxolare introduced into a benzene solution containing 3 grams of sodiumdihydro-bis(2-methoxy, ethoxy)aluminate. The mixture is warmed at 80° C.with stirring for two hours.

To the liquid reaction mixture under ice-cooling, there is added water,and the mixture is extracted with ether. The etheral extract is washedwith water, dried on magnesium sulfate, and the solvent is removed bydistillation under reduced pressure. A 10% ethanolic hydrochloric acidis added to the residue and the mixture is concentrated under reducedpressure to dryness. The residue is recrystallized from a mixture ofethanol and ethyl ether to obtain the hydrochloride of the purposedproduct with 4.1 grams of yield, and having a melting point of 219°-221°C.

Elementary analysis of the hydrochloride having the presumable formulaC₂₈ H₃₂ N₂ O₂.2HCl.1/3 H₂ O gives the following data:

    ______________________________________                                                     C       H        N                                               ______________________________________                                        Calculated (%) 67.05     6.83     5.59                                        Found (%)      67.02     6.88     5.57                                        ______________________________________                                    

Further working Examples 10-21 are conducted in accordance with theprocedure analoguous to that disclosed in the preceding Example 9. Thedata of the products thus obtained are listed in the following Table.

                                      TABLE 1                                     __________________________________________________________________________     ##STR5##                                                                                                           Elementary Analysis                                                           Calculated (%)                          No. of                Formula         Found (%)                               Example                                                                            R.sub.1                                                                           R.sub.2                                                                          R.sub.3 n (M.P. ° C)                                                                             C    H    N                             __________________________________________________________________________    10   CH.sub.3                                                                          C.sub.2 H.sub.5                                                                  CH.sub.3                                                                              3 C.sub.17 H.sub.26 N.sub.2 O.sub.2 . 2HCl .                                    2/3H.sub.2 O    54.40                                                                              7.90 7.46                                                (198°)   54.32                                                                              8.06 7.32                          11   (CH.sub.2).sub.5                                                                     CH.sub.3                                                                              2 C.sub.18 H.sub.26 N.sub.2 O.sub.2 .                                                           57.60                                                                              7.51 7.46                                                (243-249°)                                                                             57.56                                                                              7.50 7.32                          12   (CH.sub.2).sub.5                                                                      ##STR6##                                                                             2 C.sub.30 H.sub.34 N.sub.2 O.sub.2 . 2HCl .                                    1/2H.sub.2 O═° (225-229°)                                                   67.16 67.23                                                                        6.95 6.84                                                                          5.22 5.35                     13   CH.sub.3                                                                          CH.sub.3                                                                         CH.sub.3                                                                              2 C.sub.15 H.sub.22 N.sub.2 O.sub.2 .                                                           53.74                                                                              7.22 8.35                                                (249-251°)                                                                             53.38                                                                              7.38 8.38                          14   CH.sub.3                                                                          C.sub.2 H.sub.5                                                                  CH.sub.3                                                                              2 C.sub.16 H.sub.24 N.sub.2 O.sub.2  . 2HCl .                                   2H.sub.2 O      49.87                                                                              7.84 7.27                                                (221-225°)                                                                             49.90                                                                              7.77 7.40                          15   (CH.sub.2).sub.5                                                                     CH.sub.3                                                                              3 C.sub.19 H.sub.28 N.sub. 2 O.sub.2 . 2HCl .                                   1/2H.sub.2 O    57.94                                                                              7.81 7.11                                                (243-246°)                                                                             58.12                                                                              7.85 7.27                          16   CH.sub.3                                                                          CH.sub.3                                                                          ##STR7##                                                                             2 C.sub.20 H.sub.23 N.sub.2 O.sub.2 Cl . HCl .                                  1/2H.sub.2 0 (217-220°)                                                                59.56 59.41                                                                        6.01 6.23                                                                          7.00  6.93                    17   CH.sub.3                                                                          C.sub.2 H.sub.5                                                                   ##STR8##                                                                             2 C.sub.21 H.sub.25 N.sub.2 O.sub.2 Cl . 2HCl                                   (208-212°)                                                                             56.58 56.31                                                                        6.10 6.32                                                                          6.28 6.41                     18   (CH.sub.2).sub.4                                                                     CH.sub.3                                                                              2 C.sub.17 H.sub.24 N.sub.2 O.sub.2  .                                                          56.51                                                                              7.25 7.75                                                (238-242°                                                                              56.45                                                                              7.28 7.51                          19   (CH.sub.2).sub.4                                                                      ##STR9##                                                                             2  C.sub.22 H.sub.26 N.sub.2 O.sub.2  . 2HCl .                                  1/8H.sub.2 O (210-213°)                                                                61.54 61.84                                                                        6.89 6.71                                                                          6.52   6.71                   20   (CH.sub.2).sub.4                                                                      ##STR10##                                                                            2 C.sub.22 H.sub.26 N.sub.2 O.sub.2 Cl .                                        HCl (218°)                                                                             62.71 62.55                                                                        6.22 6.20                                                                          6.65  6.82                    21   (CH.sub.2).sub.4                                                                      ##STR11##                                                                            2 C.sub.29 H.sub.32 N.sub.2 O.sub.2  .                                          2HCl (242-246°)                                                                        67.83 67.78                                                                        6.67 6.72                                                                          5.46  5.42                    __________________________________________________________________________

What is claimed is:
 1. A member selected from the group consisting of acompound of the formula: ##STR12## wherein R₁ and R₂ are respectivelylower alkyl of 1 to 2 carbon atoms or both R₁ and R₂ together formdivalent alkylene of 4 or 5 carbon atoms as a part of a cyclicstructural moiety; and R₃ is lower alkyl, phenyl, halogen-substitutedphenyl or benzhydryl, and a pharmacologically acceptable acid-additionsalt thereof.
 2. A compound according to claim 1, wherein R₁ is methyl,R₂ is ethyl, and R₃ is methyl.
 3. A compound according to claim 1,wherein R₁, R₂ and R₃ are respectively methyl.